1. Field of the Invention
The present invention relates to the art of electrical connectors, and more particularly to a high speed Serial Attached SCSI (Small Computer System Interface) (SAS) connector mounted on a printed circuit board (PCB).
2. Background of the Invention
Parallel ATA (Advanced Technology Attachment) and parallel SCSI are two dominant disk interfaces technologies today. The parallel ATA disks are widely used in desktop PCs and mobile PCs, and the parallel SCSI disks are mainly used in high-volume servers and subsystems. As disk interconnect speeds continue to rise, existing parallel ATA and parallel SCSI buses are reaching their performance limits because that parallel transmissions are susceptible to crosstalk across multiple streams of wide ribbon cable that adds line noise and can cause signal errors—a pitfall that has been remedied by slowing the signal, limiting cable length or both. Therefore, new interconnect technologies are needed to meet performance requirements going forward. The serial technology is emerging as a solution to the problem. The main advantage of serial technology is that while it does move data in a single point-to-point stream, it does so much faster than parallel technology because it is not tired to a particular clock speed.
Serial ATA (SATA) is a serial version of ATA, which is expected to be a replacement for parallel ATA. U.S. Pat. No. 6,331,122 discloses a type of SATA receptacle connector for being mounted on a Printed Circuit Board. The receptacle connector has two receiving cavities defined in an insulative housing thereof and two sets of conductive contacts respectively used for power and signal transmission installed in the insulative housing. U.S. Pat. No. D469,407 discloses an electrical connector assembly with a SATA plug connector as a part thereof. The plug connector has two generally L-shaped tongue plates receiving two sets of terminals for electrically connecting the conductive contacts as the tongue plates are inserted into the respective receiving cavities of the receptacle connector.
Serial Attached SCSI (SAS) is a successor to the parallel SCSI and is also based on serial technology. Besides the advantage of higher speed signal transmission, another most significant advantage is the SAS interface will also be compatible with SATA drives. In other words, the SATA plug connector can plug directly into an SAS receptacle connector if supported in the system. By this way, the system builders are flexible to integrate either SAS or SATA devices and slash the costs associated with supporting two separate interfaces.
FIG. 1 disclosed a known Serial Attached SCSI electrical connector 9 for electrically connecting exterior electrical element to PCB. The electrical connector 9 includes a dielectric housing 91, a plurality of electrical contacts 92 received in the housing 91, and a latching element 93 for positioning the housing on the PCB. The housing 91 defines two opposite first interior sidewalls 9125 in lengthwise direction, and an engaging slot 912 is formed between said two first interior sidewalls 9125 for receiving exterior electrical element. The first interior sidewall 9125 defines a plurality of receiving slot 915 for receiving corresponding contacts 92. The electrical contacts 92 includes a first contact 921, a second contact 922, a third contact 923, and a fourth contact 924 that have different shapes with regard to each other and received in the corresponding receiving slot 915, respectively. Each contact 92 includes an end extending above the housing 91, so as to be welded on the PCB. After the electrical connector 9 is placed on the PCB, a vacuum device is used to grip the planar surface of top end of the housing 91, so as to mount the electrical connector 9 onto the desired place on the PCB quickly and accurately. But the top planar surface of the housing does not provides an area big enough facilitating to be sucked by a vacuum device, so the connector 91 cannot meet the desires of an automatic manufacture.
Furthermore, before the connector is welded onto the PCB by use the SMT (Surface mounted technology, the electrical connector needs to be heated. When temperature up to desired, because resilient force of the contact effect on the first interior sidewall 9125, the engaging slot 912 that the second contact 922 received therein contracts toward inside, in other words, the space between the two first interior sidewalls 9125 of the engaging slot 912 is smaller than before, which is to guide the exterior electrical element cannot inserting into the engaging slot 912 and some function of the electrical connector may be invalidly.
In view of the foregoing, a new and improved electrical connector is desired to solve above-mentioned problems.